Small boats playing in strong wind ?

For a single crew, I would go as short at 5 metres. However, this boat is, if I remember correctly, only 4 metres long. There was no report of how it sailed going along with the pictures, so I don't know whether the very short rig is enough to prevent excessive pitching with that short a waterline and those fine ends.

If the windward hull is shorter than the leeward hull, twisting stresses are reduced. Also, in the winds in which you want to sail, aero drag is quite high compared to the boat's momentum, making tacking more difficult. Shunting might be easier (disclaimer: I have little personal experience with proas, and none in the kind of wind you want to deal with).

You could add foil stabilisation, like so:

That also did not come with a description of how it sailed in a breeze and some waves. Model tests (I don't know whether by the same person) can be seen here:


And the same idea for a third time, illustrating the movement of the hinge a bit more clearly, though there is not enough wind and wave to demonstrate its function:


I put together this one, 23 years ago:

The intention was that I could steer the boat by grabbing any of the spars and shift the paravane fore or aft. With the deep V on this boat, that didn't work. There was only enough wind during the whole week to see that the paravane hooked in well enough, but not enough wind to find out how well it stabilised the boat (I only had the one week because I moved to a different country shortly after, and could not take the boat with me). More details are in AYRS Catalyst #23, January 2006: Catalysts – Amateur Yacht Research Society https://www.ayrs.org/catalysts/

Steering worked fine, from on the wind to a broad reach, on this boat a year earlier. If you look closely, you can see a bridle between the top of the mast and the point where it attaches to the hull. Where the two legs of the bridle meet, a line goes to the paravane that is just about visible in the water to windward:

I could not make the boat tack or gybe with the paravane only, and switching between port and starboard paravanes was a nuisance, which motivated the development of the two-way paravane:

For a one-way paravane keeping a boat upright in apparent wind speeds close to what you aim for:


And a two-way paravane at about half that speed:


If the paravane can provide enough force to suspend a pilot between it and the kite, it can certainly stabilise a small boat in the same conditions, which are a lot more benign that what you are thinking of, so that may not generalise.

And here is an entirely untested concept for a two-way paravane that might be better (or, of course, worse) than either my design from 23 years ago, or Rousson's design from about 12 years ago:

In 50 knots, it takes a skilled paddler to keep a slalom canoe upright against the wind pressure just on the paddler's body, never mind a sail, so I don't think that is a useful reference point.

For your requirements, I think the orthodox choice is a proa stabilised by your body weight as far to windward as possible.

If that is still too athletic for you, the smallest and lightest configuration that should give you the required stability would be a decked canoe with two masts, sails of perhaps 1.5 sqm, a bridle between the top of each mast and the deck, spars like I put on that little proa, lines to pull them to either end of the boat for steering, and a two-way paravane to give stability, lateral resistance, and steering. Basically, the same configuration as my little proa, only with a single, possibly water-ballasted hull with minimal lateral resistance of its own. That should be good for launching from a beach with the wind blowing roughly parallel to the beach. If the wind blows onshore, you would need to pull the boat parallel to the beach until you have pulled the paravane to weather far enough, then jump in and sheet in. Returning if the wind blows within the range of angles that makes the paravane ground before the boat does will be a problem, because the moment the paravane grounds and stops moving, it also stops providing lateral resistance and righting moment. I would not want to take such a boat into a harbour unless the wind is weak enough to paddle.

(Also, if this is a boat to be sailed off the beach, please do give it metal skids, so that you don't leave microplastics in the sand every time you sail.)

I am aware that what I propose is extremely experimental, and given the use you intend, potentially dangerous. But using any small boat as you propose will be experimental, because the more conventional ways of obtaining stability simply will not give you enough. Anything you do will need careful testing in milder conditions first.

 

Seasquirt.

I have had several notable experiences with high wind sailing.

First, I once owned a siren 17. It is sailboat with a ¾ fractional sloop rig and a 140 lb swing-keel. Once I learned how to effectively sail her, I discovered she had a high tolerance for sailing in strong winds, if I left the jib in its bag and I adjusted the swing-keel just so. I used to go out on Lake St. Clair when all the powerboats were coming in. I used to revel in small craft warnings.

But there was one time I got in over my head. I should have known. On my way down the river to the lake (which was down wind) I was reaching hull speed. But the weather reports predicted gusts up to 45 mph. And I had handled such before with the main only with a single reef. That was the condition I entered the lake in. I reefed the main before even leaving the dock. I wasn't out in the lake long before I realized I had too much sail. So I hove too and lowered the main to put a second reef in it.

While I was doing that, the head of it fluttered so violently that the halyard came untied. And once it became undone, it became a 20 ft long pennant which flew at a near right angle from the masthead. It was then that I decided I had enough. I lowered the outboard and fired it up. It started right up but proved useless, as the prop was out of the water nearly as much as when it was in it. I could make no progress back at all. I couldn't even get turned back into the wind.

So I put the second reef in the main and tried to raise it with the jib halyard. But I couldn't get enough tension to get the sail to set right. And it threatened to flutter itself to ribbons. It was then that I learned why sailors swear.
I ended up accepting a tow back to the river as soon as one was offered.

The next high wind experience I had was with my 11 foot Super Snark. It had a dagger board and a boom Lateen sail which was cut absolutely flat. The winds that day were advertised to be gusting between 20 and 30 mph. I had an exhilarating sail across the tiny lake it was on, which was mostly down wind. The tiller bowed in my hand, and a rooster-tail trailed it.

Then it was time to sail back. This was accomplished in slow stages. Even the minuscule waves of this tiny lake easily defeated the tiny fore deck and the spray rails there. I had to stop many times to bail the boat out, but I made steady progress back. I think the main reason for this was the flat cut of the sail. I was able to feather the sail without it fluttering, to the extent it produced almost no lift. This way, I was able to stop without lowering the sail to bail the boat out.

Years later, the Siren 17 and the Super Snark were long gone. I decide to design a new boat for myself. I wanted something that had the virtues of the Super Snark and the 10 ft home built scow which was my first boat. The scow was a board style boat which one sat on top of. The problem with that was that it was my first build. And it likely was the worst built boat that ever successfully sailed (after two seasons of adjustments). It leaked. And there was no way to get the water out of it, except by standing it on its transom.

I ended up designing another scow





It was to be a half-decked boat with 18 inch sides, 12ft long and 3ft wide. It was to have a balanced-lug sail of about 48sf. But like the Super Snark, I was to sit in the boat rather than on it, on top of a platform about 6in from the bottom.





This was to achieve one major goal. And that was to have a boat that could be capsized without turtling. To further insure this, two 25lb sand bags are stored under the platform. On either side of it is 60 lbs of foam flotation. What I expect will happen in a knock down is water will come in over the 3 inch side decks and swamp the boat. But once underwater, the sand ballast will keep only about 20 lbs of its 50 lb “dry weight.” Hopefully, that and its low placement will keep the boat reasonably upright for bailing out.

This boat was not designed for the purpose you have in mind.

The sail is probably wrong for the conditions you want to sail in. But I do think its design is suggestive. Its low-aspect ratio sail is less likely to knock the boat down if caught aback than a higher aspect ratio one of the same area. The vertical sides and the deep chines are likely to grip the water like a long keel, when the boat heels, allowing the boat to make windward progress even without the side-mounted dagger board. In strong wind conditions, a higher aspect ratio foil is likely to fail because the boat can not go fast enough to produce sufficient lift to overcome the topside wind drag. That and the reduced sail area doom it to stall. A long keel has to have much more area to work, because it produces lift only on the downwind side. But in this situation, this may prove a blessing, even though it comes with a substantial pointing penalty. With this hull, we get both a high aspect ratio foil and a built-in long keel. It is possible that the two together will produce enough lift to still sail to windward.

A better sail for this boat may be one I designed for my present boat.



It is basically a boom Lateen sail set on top of a balanced-lug.

When a strong wind comes up, the sail is lowered until only the boom Lateen portion is up. This cuts the sail area roughly in half and produces a sail that is less likely to flutter and has minimal twist. And because it is really two sails in one, the lower portion can have a better lift producing camber and the top one can be more flutter resistant flat.

 

Robert you're right about the 50Kn wind target being too high, which makes everything need over engineering and super strength, and is still almost impossible anyway. Probably a 40 - 45Kn, Beaufort 9, strong gale useful limit is more do-able, (just short of a Force 10 storm), and less daunting a number; I don't need to be rolled across the whitewater in a tangle of sails, sheets, and cords, looking for an emergency transmitter. I would be in safety well before 50Kn hit I think. Winds here gust to 35Kn, and rarely over 40Kn; sometimes getting over 40 in a gale or storm.

I've been looking at it from an ideal 50Kn point of view, when I should make something more practical, and then see how far I can push it.
As much as I appreciate your interest and help, I want to avoid anything potentially tangley, so no paravanes, or foils, probably no kites, and probably a monohull to keep it very simple, maybe two very short masts for balanced power.

My varied research of canoes, kayaks, hulls, and suppositions have led me to think a useful hull shape could be a broad buoyant sea kayak bow and fore end shape, blending into an 18 deg V bottom and hard chines, carried parallel through to a flat vertical transom, 14' - 15' long, and about 30" beam at gunnels. sea kayak at front, ocean speed boat at back basically. Carrying water ballast in tubes, bags, or tanks. If tacking is too difficult in high winds, gybing should be made quick, easy, and safe. I've never sailed a prau and never shunted, but gybed heaps of times, controlled, and not.

The twin masted model seen on Utube stood up to a beating very well, and a parity sized crew on deck would have drowned in those conditions. The hinged thing was novel, but extra drag and breakage points. The Swedish paravane was fast on flat water, would be no good in seas I imagine, and the sea glider is different, being suspended like that looks fun - a crow's nest without a ship. Your J type vane looks like a good invention,

Thanks sharpii2, good stories, yes strange things can happen when the wind shakes the hell out of things. After a quick release shook loose on a forestay once, I always use a screw shackle there, and tighten it well. Outboards in big chop are of little use usually; it's a common problem.
I usually try to head upwind first, so it's an easy ride home afterwards when I'm tired; or if the wind is turning, I take advantage and try to have an easy ride home.
That's a clever sail design, it reminded me of the top of a Junk rig, with the extra boom / batten used, but less ropes. You would probably need a ring to follow the gaff down the mast, preventing it from blowing out from the mast when part lowered as a lateen.

I'll look at sea kayaks some more, and see if there is a suitable test bed I can use and abuse, without making some white elephant from scratch.

 

I don't think any kind of a sea kayak is going to work for this purpose. It is too likely to flip. It has an extremely limited range of stability, maybe a few degrees. Adding an outrigger to one would make a world of difference. But you said you didn't want to mess with a multihull.

Other than scratch building a boat for this purpose, you might consider buying an old Laser and patching it up. You can make a high wind rig for it and maybe give it a more powerful rudder.

The rig could be a boom-Lateen with maybe 30 to 40 sf of area, flat cut and flat setting. The mast could then be quite short and the yard and boom could be around 10 ft each. with some aft pitch of the yard there would be some of the sail area in front of the mast. This would soften any crash jibes. And the Laser can plane. This is an ability you will want when going downwind, as it is a lot more difficult to depower the rig on that point of sail.

What I think is needed is very good form stability and a bow that won't submarine.

 

My opinion differs a bit from most of those in this thread as I don't believe a small boat has any business being out in winds above 35 knots.One with a mast sufficiently small that it's windage alone doesn't represent a major capsize threat will be lacking in power when the wind drops to more moderate levels.Perhaps there are some who have yet to read Frank Dye's books and his descriptions of the storms he encountered.One tactic was to lower the mast,which was comparatively easy with a tabernacle.

 

Frank Dye anchored to the Sea

I think we should distinguish Wind, Waves and Course: Upwind, Crosswind, Downwind

Upwind above say 33-35 knots I think the best thing to do is to stop, and if there are waves anchor in the sea taking the rudder blade out of the water.

But Crosswind can be sailed in very windy conditions.

 

I forgot another issue: the subjective perception of the wind in a small sailboat is based on gusts and not on the so-called 'scientists' wind', for example the last time I went up to Ribeira ...

Ribeira, Galicia - Wikipedia https://en.m.wikipedia.org/wiki/Ribeira,_Galicia

My recollection of that beautiful sailing is 24-28 knots on a typical 20 knot day according to the Meteorologists.

Gusts plus the difference between the apparent wind and the true wind.

So 34 (around the border between Force 7 and Force 8) sailing upwind in a small sailboat can be about 44 knots.

 

...

Fun Factor

I think it's a lot of fun to sail crosswind with a lot of wind and waves.

I mean there are clearly three worlds, almost like three planets: Up Wind, Cross Wind, Down Wind.

 

...

Jib reefed on a boom without up and down movement, i.e. the carriage, the jib car, installed on the boom that gives the orientation, i.e. the angle of attack.

 

Consider a mini transat hull, with sail-drone rig. The fixed-wing rig allows pointing higher and this reduces heeling forces correct? It would be especially useful in high winds, to carefully navigate upwind through rough seas.

Next construct the hull like sven's designs using 75mm thick divinicell with carbon on both sides. It may be a little heavier but it will also provide good insulation in cold waters. If possible put separate watertight bulkheads as well. The carbon should protect you from lightning?

Dual rudders is good for redundancy but also you can turn the rudders opposite to slow the boat like a brake and avoid crashing into waves or flying off them.

Finally, for longer runs, use kites rather than the fixed wing to pull the boat at much higher speeds when conditions allow.

 

I believe he sailed a Wayfarer. It is a very good boat. But I think a Bermudan fractional sloop is not necessarily the best rig for windy conditions. The reason for this is that, when reefed, a lot of bare mast is left exposed. And all of it is high up where the wind is strongest. In my book about working sailboats, I have noticed that the Bermudan rig was rarely used. When it was, The sail was usaully very low aspect ratio, or if of higher aspect ration, two were used. On some sharpies, two sprit boom Bermudan sails were used during the summer. During the winter, one of the sails was taken out, and the other was moved to a mast step near the center length of the boat. I can imagine the sprit snotter was tightened up in strong winds to the point that the sail was nearly dead flat.

Now, I would never advocate deliberately sailing in absolutely crazy conditions (big, menacing waves along with screaming gusts). But I recognize that in some regions one either gets a lot of wind or almost no wind at all. And often this is on small lakes that don't develope big waves. The scow I designed and built was intended to sail on such a lake. The sail, when reefed, loses a little less tha half its area (which is on the low side of moderate to begin with). what is left is a sturdy boom Lateen sail, which I hope is big enough to still drive the boat to winward.

 

Here is another design of mine. As I hope you can see, the hull is the same as the 12 footer I posted earlier. The main differnces are the deck design and the rig design. The deck has a considerable pitch, like that of a house roof. This is so that it will shed water very quickly if it should ever shunt under. This (I hope) would prevent pitch-poling. The rig is two masted to get the center of area lower and to have a good deal of control, even without a rudder. The yard is peaked higher, so when its reefed down to the boom, it forms a boom Lateen sail with a horizontle center of area pretty much where it was when the sail was full. The mizzen is really two sails, with one set below the boom and one above it. This way, the top one can be completely struck while leaving the bottom one full. This design was intended for the Everglades Challenge.

 

Thanks for everyone's input. Some very good ideas here could be combined to work. The idea is on the back burner for me for now, having 2 other boats to keep in good repair, and the wind has moderated for now, but I'm always looking for new helpful ideas towards the objective: very small boat fun in big winds. If you see anything relevant or relatable, even if they are un-tried, post about it here. Myself or some other crazy person may make something great, or barely acceptable, eventually.
I've sort of gone full circle in thinking, back to an idea I had ages ago, of a canoe/dinghy, with a steel wheel/keel, that I can push down the road to the water, without a trailer, climb in, and sail. Except a thin steel wheel and sand won't work, and pushing it up a slippery boat ramp could be difficult. Something is always too difficult !

 

What I find remarkable is the 23ft saildrone passing through a category 4 hurricane. From what I can tell it is "beating" against 90 knot winds with out issue (occasionally being flipped over)

The fixed wing sail is the ultimate for upwind in strong winds. It can have a very high angle of attack which reduces the power allowing beating in high winds. The wingsail serves as a float preventing capsize, and has the minimum windage (no rigging). The boat itself is very low profile often plowing under waves rather than over them.